BMDroid

In this DIY I will show you how to build an
android infotainment system in your beamer,

or simply to go from this

>>> to this >>>

This is the product of many months of planning, designing and brainstorming on how to put all this together. I am sharing this knowledge so you could also enjoy this experience. If you found this guide helpful, please consider making a donation.

This guide is based on an E46 and
7” Samsung Galaxy Tab 2 and if you have any other BMW the pinouts of your radio
/ cd changer interfacing might differ so you will have to find them yourself.

Disclaimer: I take no
responsibility if your car sets on fire, causes an injury, starts speaking alien
language, or causes a nuclear war. This is a guide only and every step should
be taken with caution.

Since I got that out of the way, let's begin.......Before you do anything make sure
your headunit SUPPORTS CD CHANGER,
The Black connector itself will has a white or black 10pin plug inserted into
it as pictured below:

CD Changer Connector
Note: it could be white colour as well

In addition please note - by doing this mod you will loose the ability to use FM radio on your headunit... for now...You can listen to streaming radio stations using app called TuneIn, or if your android device supports FM radio, you will be able to use that instead.

3.5mm
stereo male to male audio cable with mini plugs like these. They are very similar to the plugs found on the headphones and audio cables that Apple use.

BMW HVAC Relocation Kit - to move your aircon controls down one slot. For a part number check out realoem, It is in Vehicle Trim section under Centre armrest / oddments trays where you will find Storing Partition Mounting Parts section. It is part 1 called Carrier, but be careful to choose the right one as there are several options. Check it out here

Before we start taking things apart, make sure you have your Android device set up and you have all your favourite software installed. Make sure you have Tasker and for a start just have 2 profiles in it to keep the screen ON when charger connected (any source) and turn screen OFF when charger disconnected. These are very easy to set up, but if you have troubles let me know.

Note: I didn't have any photos of the "before" state of my dash, so just ignore installed tablet on the photos

ALWAYS DISCONNECT YOUR BATTERY WHEN WORKING WITH THE WIRING

1 - Remove the trim by inserting butter knife underneath the trim above the glove box and plying it out - it will come out very easily:

1.1 - Next remove the trim above your stereo:

1.2 - Remove 2 screws holding the stereo and remove the stereo:

1.3 - Now is a good time to connect your CD Changer Interface (I will call it Grom form now on) as per instructions from GromAudio website. Make sure you test it and it all works as you expect it to work: by
switching your headunit to CD mode and connecting 3.5mm cable from gromaudio to your
phone or tablet and playing some music. Make
sure you LEAVE THE HEADUNIT IN CD MODE this is very important you do that - and switch the ignition off - disconnect
the headunit and remove it completely.

1.4 - Now with the headunit removed, insert your hand into the space where headunit was and give the Aircon a push from behind. The Aircon unit will pop out. Disconnect all the wiring and put it aside.

1.5 - Remove 2 screws that hold the top air vents:

1.6 - Hive the air vents a push from behind. Use a little bit of force and be prepared that they will jump out at you. Once they are out - put them on top of the dash.

1.7 - Undo 2 screws at the very bottom corners, remove the whole carry tray and put it aside:

As you can see my tray is a bit broken so be careful with yours as the plastic is a bit soft.

The rounded metal terminals are you negative terminals. Note where they connect on the PCB and cut them completely off. The metal terminal with a spring is your positive terminal. Note where it is connected to the PCB and cut it off. What you should get in the end is the PCB with no metal sticking out of it. Like so:

3.1 - Now you need to connect a bit of wire to each of the terminals. Use colour coded wires for easy identification of positive (in my case Red) and negative (Black) terminals. Solder Red wire to the Positive terminal on a PCB you noted in the previous step, and Black wire to the negative - like so:

3.2 - Now you need to connect it to the car Accessory wire. For this we need to know the pinouts of the Headunit Connector. Here are the pinouts for the 17pin and 40pin headunit plugs:

What we want here is to locate a GND (Ground) and 12V ACC (Accessory terminal). This wire becomes live when we switch the ignition to the 1st position. Look closely on the headunit's plug - you will see the numbers indicating every pin. Connect Black wire from the USB charger to the GND wire that comes out of the headunit's plug and Red wire to the 12V ACC wire that comes out of the plug. The schematic of the connection looks like this:

Note: you need to make connections IN-LINE meaning the original wire that goes into the headunit's plug must not be broken! So you attach your wire to the original wire. I made a couple of photos trying to chow you what i mean:

I have managed to put the USB charger back in its housing, which didn't close any more, but nothing that couldn't be fixed with some electrical tape. Then I mounted it to the reinforcing structure inside the dash:

4 - Mounting tablet into the bezel. Your bezel will probably arrive without any kind of mounting solution, so it is up to your imagination. I will show you what I have done here. I got 2 thin aluminium strips - they are probably 1-1.5mm think. I then bent them around the tablet and made holes for 4 short screws. I have also attached the soft fluffy side of velcro to the tablet and the hook side of the velcro I have attached to each of the aluminium strips. Then, after careful alignment of the tablet's screen to the window of the bezel i used some paper tape to temporary secure the position of the tablet and the bezel:

To temporary secure the tablet's location I used 4 bits of tape to stick the tablet to the bezel. Stick the tape directly over the screen and over the frame.

So I have put it all together and secured the aluminium strips with the 4 screws and then I discovered that I was unable to plug the 3.5mm audio cable into the tablet as well as the USB cable because the bezel was in the way. So I had to make some modifications to the Bezel:

I had to cut the aluminium strip a little because it was in the way of the USB plug and shave some of the bezel off that caused the plug to be on an angle.

After I was satisfied with the tablet's position inside the window and the way the 3.5mm audio and USB cables are plugging in - I attached the strips and secured them with 4 screws:

Aluminium strips mounted to the bezel. Under each strip is velcro - preventing the tablet from moving.

My headunit had a bit of a brutal treatment but nothing that is irreversible - which is good I guess.

Remember, how in step 1.3 you had to leave the headunit in CD mode. Well NOW is the best time to double check that - you won't have this easy opportunity to do that again. Just connect it back in the car and turn ignition to ACC position - it should still be in CD mode.

Let's begin taking the bits off of it:

Don't mind the look of it as i have pre-dismantled it already.

Take the top cover off:

There should be couple of screws holding the Tape assembly - undo them and unplug the whole tape assembly:

5.1 - Push towards yourself on these clips with a flat screwdriver and carefully unplug the ribbon cables:

5.2 - Unplug the volume knob:

5.3 - Now you need to detach the whole faceplate from the headunit but unclipping the plastic lip from the aluminium casing:

Ignore that bent casing for now - it will make sense in the next section.
Also ignore the plugs i made there - those were previously for the AUX input in Tape mode - they are unused any more and I didn't bother taking them out.

Closeup of the bent corner.

Headunit in the carry tray

And this is pretty much how we hide the headunit behind the tablet. Don't worry it works perfectly fine without the faceplate - yeah I was surprised too about this discovery...

This is also a good time to test this: Connect the headunit to the car and play something over your Grombox 3.5mm audio cable - you should get the sound and should still be able to control the volume on the steering wheel.

Now we need to put these together on a table. There will be a bit of cutting of the carry tray involved and bending or shaving off the corner of the headunit you saw earlier. I didn't do cutting of the tray with anything fancy but a pair of large wire clippers so it does look ugly but no one can see it anyway so who cares :) Same goes with the headunit. I decided to bend the corner away instead of cutting it off.

Basically what you want to do here is to put the headunit into the tray where it belongs - push it way to the back. Then attach bezel with the tablet to the carry tray and cut off / bend bits that are in the way - simple:

This is what modifications i did to the tray and the headunit's casing:

Upside down view of the tray cut and headunit's corner

All the cuts made.

This is tray and bezel with tablet view from upside down. This is why the headunit 's corner needs to be bent / cut

Another photo of the modification to the headunit's casing.

So in the end you should get something like this:

Note how the tablet sticks out a little bit from the top - this is normal and it should not get in a way of the dash trim that goes over-top.

7.5 - Push the bezel into place, mind the cables on both sides. Bezel goes into the dash quite tightly so apply a bit of force to push it in. Once it is in the dash - give the music a test and the secure the bezel with 2 screws:

I am in the process of making a hardware interface to connect Android device with IBUS. It is in the early prototype stage but I hope it will be ready and have first simple functionality in the coming months.

This is the product of many months of planning, designing and brainstorming on how to put all this together. I am sharing this knowledge so you could also enjoy this experience. If you found this guide helpful, please consider making a donation.